Home prices in most major metropolitan areas continue increasing, according to the latest Case-Shiller Index released Tuesday. Nationally, prices rose 2.6% in August compared with a year earlier.

Chicago saw the largest price gain (+5%) of the country’s 20 largest cities, followed by New York (+4.98) and Detroit (+4.8%). The Midwest was the strongest region in the country for housing price gains, averaging an increase of 3.9%. The Northeast ranked second, increasing 3.8%.

“On a year-to-date basis, the national composite has risen 5.8%, which is well above the median full calendar year increase in more than 35 years of data,” S&P Dow Jones Indices Managing Director Craig J. Lazzara said in a statement. The increases mark the seventh consecutive monthly gain since home prices troughed in January.

“The year’s increase in mortgage rates has surely suppressed housing demand, but after years of very low rates, it seems to have suppressed supply even more,” he said. “Unless higher rates or other events lead to general economic weakness, the breadth and strength of this month’s report are consistent with an optimistic view of future results.”

The only exceptions to the rosy data were in the Western and Southwestern parts of the country. Prices decreased in seven of the country’s largest metropolitan areas in August. Las Vegas saw the largest price decline (-4.9%), followed by Phoenix (-3.9%), San Francisco (-2.5%), Dallas (-1.7%), Portland (-1.5%), Seattle (-1.5%) and Denver (-0.6%).

The prospects for would-be homebuyers are already grim, with mortgage rates of about 8% and new home listings at near-record lows.

The median monthly mortgage payment last week was 10% higher than a year ago, according to an analysis from the real estate listing web site, Redfin. The median sale price of a home last week was $369,075 — up 3.1% from a year earlier. The median asking price was up 5.4% to $384,375, marking the biggest increase in a year. Almost 30% of homes are selling above list price.